Merge branch 'search-git-grep' into 'master'

Implement faster search of code (via git grep)

Much faster than iterating over each file using rugged.

Performance compare for Linux repository using keyword `sha`:

```
OLD: 250 seconds
NEW: 9 seconds
```

See merge request !957

1 files changed, 24 insertions, 0 deletions

diff --git a/spec/models/repository_spec.rb b/spec/models/repository_spec.rb
index a083dcb1274..d25351b0f0e 100644
--- a/spec/models/repository_spec.rb
+++ b/spec/models/repository_spec.rb
@@ -47,4 +47,28 @@ describe Repository do
       it { is_expected.to be_falsey }
     end
   end
+
+  describe "search_files" do
+    let(:results) { repository.search_files('feature', 'master') }
+    subject { results }
+
+    it { is_expected.to be_an Array }
+
+    describe 'result' do
+      subject { results.first }
+
+      it { is_expected.to be_an String }
+      it { expect(subject.lines[2]).to eq("master:CHANGELOG:188:  - Feature: Replace teams with group membership\n") }
+    end
+
+    describe 'parsing result' do
+      subject { repository.parse_search_result(results.first) }
+
+      it { is_expected.to be_an OpenStruct }
+      it { expect(subject.filename).to eq('CHANGELOG') }
+      it { expect(subject.ref).to eq('master') }
+      it { expect(subject.startline).to eq(186) }
+      it { expect(subject.data.lines[2]).to eq("  - Feature: Replace teams with group membership\n") }
+    end
+  end
 end